The recalls follow the discovery of Salmonella at Diamond Pet Food's Gaston, South Carolina facility. Diamond earlier recalled several of its dry dog foods and federal officials said at least 14 people have been infected with Salmonella, apparently after coming into contact with the contaminated pet food.

It's the same South Carolina plant that a few years ago produced Nutra Nuggets and other dog foods contaminated with aflatoxin, a mold, which was blamed for the death of dozens of dogs. In 2008, Diamond agreed to a $3.1 million settlement to compensate dog owners.

It often comes as a surprise to consumers to learn that their trusted brand of pet food is manufactured, at least partly, at the same plant as other brands. Manufacturers keep costs down by outsourcing at least part of their production process, adding proprietary flavorings or ingredients to differentiate their products from the competition.

The recalls are a major embarrassment for companies that promote their products as being more "natural" than their competitors.

Peace of mind

"As a pet parent myself, I know how important peace of mind is when it comes to the health of our pets, and that is why we require that all of our products undergo testing forSalmonella, among other things," said Tim Callahan, chief executive officer of WellPet, the maker of Wellness products. "All of these lots tested negative prior to being released for sale. We are voluntarily taking this additional step to further safeguard our dogs and to put our customers’ minds at ease."

Callahan said the majority of Wellness natural products for pets are produced in WellPet's own facility in Mishawaka, Indiana, and he said WellPet "no longer purchases any products from Diamond Pet Foods."

PhotoOn April 2, 2012, the Michigan Department of Agriculture and Rural Development detected Salmonella in an unopened bag of Diamond Naturals Lamb Meal & Rice dry dog food, which had been collected March 14, 2012, during routine retail testing of dry pet food, the CDC said. A sample of Diamond Puppy Formula dry dog food collected by FDA during an inspection at the South Carolina production facility has also yielded Salmonella.

Public health investigators identified recent cases of human illness matching the Salmonella Infantis strain found in the unopened bag of dry dog food produced by Diamond Pet Foods. In interviews, ill persons answered questions about contact with animals and foods consumed during the week before becoming ill. Seven of ten reported contact with a dog in the week before becoming ill.

More illnesses are likely to be discovered in the coming weeks as records are collected and analyzed from health departments around the country.

Danger to humans

If you're a pet owner, health officials say it's important to be careful handling pet food and pet dishes. You should wash your hands thoroughly after handling pet food. Pet food and feeding dishes should be kept out of the reach of children. Dishes should be washed often and thoroughly.

Pets with Salmonella infections may have decreased appetite, fever and abdominal pain. If left untreated, pets may be lethargic and have diarrhea or bloody diarrhea, fever and vomiting. Infected but otherwise healthy pets can be carriers and infect other animals or humans. If your pet has consumed the recalled product and has these symptoms, please contact your veterinarian.

Individuals handling dry pet food can become infected with Salmonella, especially if they have not thoroughly washed their hands after having contact with surfaces exposed to this product. People who believe they may have been exposed to Salmonella should monitor themselves for some or all of the following symptoms: nausea, vomiting, diarrhea or bloody diarrhea, abdominal cramping and fever.

According to the Centers for Disease Control, people who are more likely to be affected by Salmonella include infants, children younger than 5 years old, organ transplant patients, people with HIV/AIDS and people receiving treatment for cancer.